Little Jack Davidson’s first day at school was especially emotional for mum Tracey - it was a day she once feared she would never see.

The brave Billingham four-year-old was born with only half a heart, and has already undergone three major operations.

The youngster is enjoying a much improved tolerance for exercise after the most recent surgery in December 2011.

He will, however, still need a heart transplant before he reaches 30, as previously reported.

Jack, who lives with mum Tracey, 34, and dad Ian, 40, has been attending the pre-school at Billingham South Primary School for two years, but this week he moved up to the big school proper.

“This is a massive milestone for us,” said Tracey.

“Jack was fine about it, but I was a bit emotional.

“This was a milestone we potentially didn’t think we would ever reach.

“Jack’s been going to the nursery at Billingham South for a while. But when I said to him ‘It will be funny coming here and not going to the nursery’ I saw his little face. But then he was OK.”

Jack was born with a condition that affects just one in 20,000 babies.

Tracey, a paediatric nurse, understands the condition would have been unsurvivable 15 years ago. But thanks to advances in medical science, her baby son was given a fighting chance that he grasped with both of his tiny hands.

He underwent the first of his open heart surgeries at just six weeks old at Newcastle’s Freeman Hospital.

Jack’s condition, and future transplant, will always play on his parents’ minds. But for now they are enjoying the milestone of their courageous son’s first week at school.

And despite his condition, Jack, who turns five on September 16, is now a typical little boy with “tons of energy”.

Tracey works 12-hour shifts and will miss seeing more of her son now he is at school full time. But she is full of pride at seeing him in his uniform.